GNOME Software now displays version and size information for non-installed applications;

enabled the Snappy backend.

Those interested in testing the latest GNOME Software from the Proposed repository should see THIS page. Note that the Proposed repository is for testing purposes only and may introduce instability! Also, the option to enable the Proposed repository was moved to the "Developer Options" tab in Software & Updates in the latest Ubuntu 16.04.

Until the update is available in the main repositories, you can use GDebi GTK (or dpkg via command line) to install deb files. Check out our Things To Do After Installing Ubuntu 16.04 article for how to install and set GDebi GTK to open deb files, along with other tweaks.